Flame retardant agents for thermoplastic products



3,530,164 FLAME RETARDANT AGENTS FOR THERMOPLASTIC PRODUCTS Helen Currier Gillham, Princeton, N.J., and Allan Ellis Sherr, Norwalk, and Harvey Gerald Klein, Stamford, Conn., assignors to American Cyanamid Company, Stamford, Conn., a corporation of Maine No Drawing. Continuation-impart of application Ser. No. 296,364, July 19, 1963. This application Aug. 13, 1965, Ser. No. 479,599

Int. Cl. C09k 3/28 US. Cl. 260-45.8 12 Claims ABSTRACT OF THE DISCLOSURE This invention relates to flame-retardant compositions comprising thermoplastic polymers containing a fiameretarding amount of a monophosphonium halide having the formula 1 rwherein R, R R and R are, individually, alkyl (C -C alkenyl (C -C cyano, hydroxy, irnidazolyl, and carboxy substituted alkyl (C C aryl C C aralkyl (C C vinyl, halo, polyhalo, and nitro ar-substituted aralkyl (CP C dialkylaminoalkyl (C C carboalkoxyalkyl (C -C carboxyalkenyl (C 43 or carboalkoxyalkenyl (C -C radicals, and X is a bromine, chlorine or iodine radical.

This application is a continuation-in-part of our copending application, Ser. No. 296,364, filed July 19, 1963 and now abandoned.

The use of various materials incorporated into thermoplastic resins in order to improve the flame-retardance thereof has been known in the prior art. Many compounds are commercially available for such a use, among them being chlorostyrene copolymers, chlorinated parafiin Iwax with triphenyl stibine, chlorinated parafiins and aliphatic antimonyl compounds, as well as antimony oxide-chlorinated hydrocarbon mixtures. A drawback, however, of these compounds has been the fact that generally a large amount, i.e. upwards of 35%, of additive must be incorporated into the resin in order to make it sufficiently flame-retardant. Also these prior art additives tend to crystallize or oil out of the resin after a relatively short time of incorporation.

We have now found a group of compounds which may be added to thermoplastic resins in relatively small amounts and still result in the production of satisfactory flame-retardant compositions while not crystallizing or oiling out of the resin after incorporation therein.

The production of thermoplastic resin compositions which are flame-retardant, i.e. have high resistance to heat, is of considerable commercial importance. For example, such articles as castings, moldings, foamed or laminated structures and the like are required, or at least desired, to be resistant to fire and flame and to possess the ability to endure heat iwithout deterioration. Typical illustrations of such applications can be found in castings for live electrical contacts which should not be ignited or deteriorated by heat and sparks. Structural members such United States Patent as pipes, wall coverings, Wall paneling, windows, items such as ash trays, waste baskets and the like are further examples of plastic products wherein flame-retardance is desirable.

It is therefore an object of the present invention to provide novel flame-retardant thermoplastic resin compositions.

It is a further object of the present invention to provide flame-retardant compositions comprising thermoplastic polymers and a flame-retarding amount of a monophosphonium halide, such as those represented by Formula I, above.

It is a further object of the present invention to provide novel compounds which impart flame-retardance to polymeric materials and are represented by Formula II, above.

These and further objects will become more apparent to those skilled in the art upon reading the more detailed description set forth hereinbelow.

THE THERMOPLASTIC POLYMERS Additionally, however, thermoset type materials may be employed such as the polyester resins, polyurethanes, and the like. Examples of the vinyl type polymers which; may be used to form our novel compositions are the vinyl halides, the vinylidene halides, the vinyl acetates, polyvinylbutyral, butadiene copolymers, acrylonitrilebntadiene-styrene polymers, the acrylonitriles, etc. Additionally and preferably, one may incorporate the flameretardant agents mentioned above into such polymers as the styrene polymers, i.e. polystyrene, etc., the a-olefin polymers, such as the homopolymers and copolymers etc. containing, as the major constituent, ethylene, propylene, and the like and the acrylate and methacrylate polymers produced from monomers having the formula OHz=CC R OR" wherein R is hydrogen or a methyl radical and R is hydrogen or an alkyl radical having from 1 to 6 carbon atoms, inclusive. Examples of monomers represented by Formula II include methyl acrylate, ethyl acrylate, npropyl acrylate, isopropyl acrylate, n-butyl acrylate, tbutyl acrylate, isobutyl acrylate, n-amyl acrylate, t-amyl acrylate, *hexyl acrylate and their corresponding alkyl methacrylates.

Also such polymers as the nylons, e.g. adipic acidhexamethylenediamine reaction products, the polyformaldehydes, cellulose acetate (and/or butyrate, etc.), the polycarbonates, i.e. phosgene-bisphenol A reaction prod ucts, the so-called impact polymers, i.e. rubber-polymer blends such as blends of polystyrene with 510% of butadiene-styrene, etc. may 'be made flame-retardant by the incorporation therein of the phosphonium halides more specifically discussed hereinbelow.

Additional examples of monomers which may be used to form the thermoplastic vinyl polymers encompassed by the present invention, polymerized either singularly or in combination with each other or with the other com pounds set forth hereinabove, are such monomers as the unsaturated alcohol esters, more particularly the allyl, methallyl, vinyl, methvinyl, butenyl, etc., unsaturated esters of aliphatic and aromatic monobasic acids such, for instance, as acetic, propionic, butyric, crotonic, succinic, glutaric, adipic, maleic, fumaric, itaconic, benzoic, phthalic, terephthalic, benzoylphthalic, etc., acids; the saturated monohydric alcohol esters, e.g., the methyl, ethyl, propyl, isopropyl, butyl, sec.-butyl, amyl, etc., esters of ethylenically unsaturated aliphatic monobasic acids, illustrative examples of which appear above; vinyl cyclic compounds (including monovinyl aromatic hydrocarbons), e.g., m-, and p-chlorostyrenes, -bromostyrenes, -fluorostyrenes, -methylstyrenes, -ethylstyrenes, -cyanostyrenes, the various poly-substituted styrenes such, for example, as the various di-, tri-, and tetra-chlorostyrenes, -bromostyrenes, -fluorostyrenes, -methylstyrenes, -ethylstyrenes, -cyanostyrenes, etc., vinyl pyridine, divinyl benzene, diallyl benzene, the various allyl cyanostyrenes, the various alpha-substituted styrenes and alpha-substituted ring-substituted styrenes, e.g., alpha-methyl styrene, alphamethyl-para-methyl styrene, etc.; unsaturated ethers, e.g., ethyl vinyl ether, diallyl ether, etc.; unsaturated amides, for instance, N-allyl caprolactam, acrylamide, and N-substituted acrylamides, e.g., N-methylol acrylamide, N-allyl acrylamide, N-methyl acrylamide, N-phenyl acrylamide, etc.; unsaturated ketones, e.g., methyl vinyl ketone, methyl allyl ketone, etc.; methylene malonic esters, e.g., methylene methyl malonate, etc. and ethylene.

Other examples of monomers that can be used as polymers to form the resin portion of our novel flame-retardant compositions are the vinyl halides, more particularly, vinyl fluoride, vinyl chloride, vinyl bromide and vinyl iodide, and the various vinylidene compounds, including the vinylidene halides, e.g., vinylidene chloride, vinylidene bromide, vinylidene fluoride, and vinylidene iodide, other comonomers being added, if needed, in order to improve the compatibility and copolymerization characteristics of the mixed monomers.

More specific examples of allyl compounds that can be polymerized to useful polymers, useful in the production of our novel flame-retardant compositions, are allyl alcohol, methallyl alcohol, diallyl carbonate, allyl lactate, allyl alphahydroxyisobutyrate, allyl trichlorosilane, diallyl phthalate, diallyl methylgluconate, diallyl tartronate, diallyl tartrate, diallyl mesaconate, the diallyl ester of muconic acid, diallyl chlorophthalate, diallyl dichlorosilane, the diallyl ester of endomethylene tetrahydrophthalic anhydride, triallyl tricarballylate, triallyl cyanurate, triallyl citrate, triallyl phosphate, tetrallyl silane, tetrallyl silicate, hexallyl disiloxane, allyl diglycol carbonate, etc. Other examples of allyl compounds that may be employed are given, for example, in US. Pat. No. 2,510,503, issued June 6, 1950.

These above mentioned monomers may be polymerized, copolymerized, etc., in any known manner such as by free-radical generating catalysts, irradiation, anion and cation type catalysts and the like, said method of polymerization forming no part of the present invention.

THE MONOPHOSPHON'IUM HALIDES A preferred group of phosphonium halides, however, are those represented by Formula I. The monophosphonium halides may be incorporated into the resins in flameretarding amounts, i.e. generally amounts ranging from about 1%, by weight, to about 35%, by weight, preferably to 25%, by weight, based on the weight of the polymer, have been found sufficient. A further group of preferred monophosphonium halide compounds useful in producing our novel compositions are those wherein three of R, R R and 3 are cyanoethyl or phenyl radicals.

That is to say, the flame-retardant monophosphonium halide additive may be added to the resin by milling the resin and the halide on, for example, a two-roll mill, in a Banbury mixer, etc., or the halide may be added by molding the halide and resin simultaneously, extruding the halide and resin or by merely blending the resin in powder form with the halide and thereafter forming the final desired article. Additionally, the monophosphonium halide may also be added during the resin manufacture,

i.e., during the monomer polymerization procedure, provided the catalyst, etc. conditions and ingredients of the polymerization system are inert to the monophosphonium halide.

The monophosphonium halides set forth hereinabove may be produced in any known manner without varying from the scope of the present invention. Various methods for the production of phosphonium halides of this type are disclosed in, for example, articles by Rauhut et al., J. Org. Chem., volume 28, page 473, 1963; Grayson et al., J. Am. Chem. Soc., volume 81, page 4806, 1959; Grayson et al., I. Am. Chem. Soc., volume 82, page 3922, 1960; US. Pat. 3,005,013 to Grayson et al., patented Oct. 17, 1961; Rauhut et al.. patent application, Ser. No. 211,412, filed July 20, 1962 and these articles and patents are hereby incorporated herein by reference.

Those phosphonium halides represented by FormulaI may be produced by reacting a compound of the formula with a compound having the formula R Y wherein R, R R R and X are as defined above in regard to Formula I under the following conditions: heat, toa temperature ranging from about 0 C. to about 150 C., a solution of the halide and tertiary phosphine in an appropriate solvent, such as butanol, acetonitrile and the like, for from 1 to 24 hours. The phosphonium halide is isolated by filtration, in the case of an insoluble product, by precipitation with ethyl ether or by evaporation of the solvent. Yields usually are from to of the theoretical, said procedures, however, forming no part of the present invention.

In any of said procedures wherein an unsaturated radical is present in the phosphine or the halide, a polymerization inhibitor such as hydroquinone is preferably added to retard the polymerization of the compound produced.

The imidazolyl compounds may alternatively be pre pared by reacting, under the conditions specified above in regard to the other monophosphonium halides, a compound such as tributylvinylphosphonium bromide or tricyclohexylvinylphosphonium bromide, etc., with an appropriately substituted imidazole, e.g., 2-methyl imidazole by refluxing in a suitable solvent. The products are then recovered by filtration.

The carboxyalkyl compounds may also be produced via another mechanism according to the equation:

ofinfii Chrome 0 OEDalCl- The first step is accomplished at 80 to C. under a nitrogen atmosphere for about 3 hours while the second step is conducted at room temperature and recovery is by subsequent water evaporation.

Examples of compounds which are useful in producing the novel compositions of the present invention, include tetramethylphosphonium chloride, bromide and iodide, tetraethylphosphonium chloride, bromide and iodide, tetra-n-propylphosphonium chloride, bromide and iodide, tetraisopropylphosphonium chloride, bromide and iodide, tetra-n-butylphosphonium chloride, bromide and iodide, tetra-t-butylphosphonium chloride, bromide and iodide, tetraisobutylphosphonium chloride, bromide and iodide, tetrapentyphosphonium chloride, bromide and iodide, tetrahexylphospbonium chloride, bromide and iodide,

tetraheptylphosphonium chloride, bromide and iodide,

tetraoctylphosphoninum chloride, bromide and iodide,

tetravinylphosphonium chloride, bromide and iodide,

tetraallylphosphonium chloride, bromide and iodide,

tetrapropenyl-l-phosphonium chloride, bromide and iodide,

tetra-1-butenylphosphonium chloride, bromide and iodide,

tetra-Z-butenylphosphonium chloride, bromide and iodide,

tetra-l-or-2-pentenylphosphonium chloride, bromide and iodide,

tetra-1;-2-or-3-hexenylphosphonium chloride, bromide and iodide,

tetra-1-;-2-or-3-heptenylphosphonium chloride, bromide and iodide,

tetra-1-;-2-;-3-or-4-ocetnylphosphonium chloride, bromide and iodide,

tetracyanomethylphosphonium chloride, bromide and iodide,

tetra-2-cyanoethylphosphonium chloride, bromide and iodide,

tetra-Z-cyanopropylphosphonium chloride, bromide and iodide,

tetra-3-cyanopentylphosphonium chloride, bromide and iodide,

tetra-Z-cyanohexylphosphonium chloride, bromide and iodide,

tetra-4-cyanohexylphosphonium chloride, bromide and iodide,

tetra-3-cyanheptylphosphonium chloride, bromide and iodide,

tetra--cyanooctylphosphonium chloride, bromide and iodide,

tetrahydroxymethyphosphonium chloride, bromide and iodide,

tetra-Z-hydroxyethylphosphonium chloride, bromide and iodide,

tetra-2-hydroxypropylphosphonium chloride, bromide and iodide,

tetra-3-hydroxypentylphosphonium chloride, bromide and iodide,

tetra-4-hydroxyhexylphosphonium chloride, bromide and iodide,

tetra-fi-hydroxyhexylphosphonium chloride, bromide and iodide,

tetra-3-hydr0Xyheptylphosphonium chloride, bromide and iodide,

tetra-8-hyroxyoxtylphosphonium chloride, bromide and iodide,

tetracarboxylmethylphosphonium chloride, bromide and iodide,

tetra-Z-carboxyethylphosphonium chloride, bromide and iodide,

tetra-2-carboxypropylphosphonium chloride, bromide and iodide,

tetra-3-carboxypentylphosphonium chloride, bromide and iodide,

tetra-5-carboxyhexylphosphonium chloride, bromide and iodide,

tetra-7-carboxyheptylphosphonium chloride, bromide and iodide,

tetra-1-carboxyoctylphosphonium chloride, bromide and iodide,

tetraimidazolylmethylphosphonium chloride, bromide and iodide,

tetra-2-imidazolylethylphosphonium chloride, bromide and iodide,

tetra-3-imidazolylpropylphosphonium chloride, bromide and iodide,

tetra-5-imidazolylpentylphosphonium chloride, bromide and iodide,

tetra-Z-imidazolylbutyphosphonium chloride, bromide and iodide,

tetra-3-cyanobutylphosphonium chloride, bromide and iodide,

tetra-3-hydroxybutylphosphonium chloride, bromide and iodide,

tetra-4-carboxybutylphosphonium chloride, bromide and iodide,

tetra-2-imidazolylhexylphosphonium chloride, bromide and iodide,

tetra-3-imidazolylheptylphosphonium chloride, bromide and iodide,

tetra-8-imidazolyloctylphosphonium chloride, bromide and iodide,

tetraphenylphosphonium chloride, bromide and iodide,

tetratolylphosphonium chloride, bromide and iodide,

tetraxylylphosphonium chloride, bromide and iodide,

tetra-u-methylphenylphosphonium chloride, bromide and iodide,

tetranaphthylphosphonium chloride, bromide and iodide,

tetrabenylphosphonium chloride, bromide and iodide,

tetra-2-phenethylphosphonium chloride, bromide and iodide,

tetra-wmethylbenzylphosphonium chloride, bromide and iodide,

tetra-a-ethylbenzylphosphonium chloride, bromide and iodide,

tetra-4-phenylbutylphosphonium chloride, bromide and iodide,

tetra-5-phenylpentylphosphonium chloride, bromide and iodide,

tetra(o, m or p-vinylbenzyl)phosphonium chloride,

bromide and iodide,

tetra(o, m or p-chloro, bromo, fiuoro or iodobenzyDphosphonium chloride, bromide and iodide,

tetra(o, m or p-dichloro, dibromo, difiuoro or diiodobenzyl)phosphonium chloride, bromide, and iodide,

tetra(o, m or p-nitrobenzyl)phosphonium chloride,

bromide and iodide,

tetra(o, m or p-vinyl-Z-phenethyl)phosphonium chloride,

bromide and iodide,

tetra(o, m or p-chloro-2-phenethyl)phosphonium chloride, bromide and iodide,

tetra(o, m or p-dibrom,o2-pheneth.yl)phosphonium chloride, bromide and iodide,

tetra(o, m or p-nitro-Z-phenethyl)phosphonium chloride,

bromide and diode,

tetra(o, m or p-vinyl-wmethylbenzyl)phosphonium chloride, bromide and iodide,

tetra(o, m or p-fluoro-a-methylbenzyl)phosphonium chloride, bromide and iodide,

tetra(o, m or p-trichloro-a-methylbenzyl)phosphonium chloride, bromide and iodide,

tetra(o, m or p-nitro-a-methylbenzyl)phosphonium chloride, bromide and iodide,

tetranaphthylmethylphosphonium chloride, bromide and iodide,

tetra(vinyl, chloro, dibromo or nitro err-substituted naphthylmethyl)phosphonium chloride, bromide and iodide,

tetra(dimethylaminomethyl)phosphonium chloride,

bromide and iodide,

tetra(diethylaminomethyl)phosphonium chloride,

bromide and iodide,

tetra(diethylaminoethyl)phosphonirum chloride,

bromide and iodide,

tetra(butylmethylaminomethyl) phosphonium chloride,

bromide and iodide,

tetrakis(carbomethoxymethyl)phosphonium chloride,

bromide, and iodide,

tetrakis(carboethoxymethyl)phosphonium chloride,

bromide and iodide,

tetrakis(carbomethoxyethyl)phosphonium chloride,

bromide and iodide,

tetrakis(Z-carboethoxyethyl)phosphonium chloride,

bromide and iodide,

tetrakis 3-carboethoxypropyl phosphonium chloride,

bromide and iodide,

tetrakis 2-carbo ropoxyethyl) phosphonium chloride,

bromide and iodide,

tetrakis (carbobutoxymethyl) phosphonium chloride,

bromide and iodide,

tetrakis 3-carbopropoxypropyl phosphonium chloride,

bromide and iodide,

tetrakis carb opentoxymethyl phosphonium chloride,

bromide and iodide,

tetrakis(4-carboethoxybutyl)phosphonium chloride,

bromide and iodide,

tetrakis carbomethoxyvinyl) phosphonium chloride,

bromide and iodide,

tetrakis(Z-carbomethoxyallyl)phosphonium chloride,

bromide and iodide,

tetrakis(carboethoxyvinyl)phosphonium chloride,

bromide and iodide,

tetrakis carbobutoxyvinyl) phosphonium chloride,

bromide and iodide,

tetrakis Z-carbomethoxy-Z-butenyl phosphonium chloride, bromide and iodide,

tetrakis 2-carbomethoxy-3-pentenyl) phosphonium chloride, bromide and iodide,

methyltriphenylphosphonium chloride, bromide and iodide,

ethyltriphenylphosphonium chloride, bromide and iodide,

propyltriphenylphosphonium chloride, bromide and iodide,

benzyltriphenylphosphonuim chloride, bromide and iodide,

p-nitrobenzyltriphenylphosphonium chloride, bromide and iodide,

2,4-dichlorobenzyltriphenylphosphonium chloride,

bromide and iodide,

carboethoxymethyltriphenylphosphonium chloride,

bromide and iodide,

tris 2-cyanoethyl) methylphosphonium chloride,

bromide and iodide,

tris(2-cyanoethyl)-ethylphosphonium chloride, bromide and iodide,

tris(2-cyanoethyl)octylphosphonium chloride, bromide and iodide,

tris(2-cyanoethy1)allylphosphonium chloride, bromide and iodide,

benzyltris(2-cyanoethyl)phosphonium chloride, bromide and iodide,

2,4-dichlorobenzyltris 2-cyanoethyl) phosphonium chloride, bromide and iodide,

2,5-dichlorobenzyltris(Z-cyanoethyl)phosphonium chloride, bromide and iodide,

3,4-dichlorobenzyltris(2-cyanoethyl)phosphonium chloride, bromide and iodide,

2,4-diiodobenzyltriphenylphosphonium chloride, bromide and iodide,

2,5-difluorobenzyltriphenylphosphonium chloride,

bromide and iodide,

3,4-dibromobenzyltriphenylphosphonium chloride,

bromide and iodide,

2-hydroxyethyltriphenylphosphonium chloride, bromide and iodide,

tris Z-cyanoethyl) -2-hydroxyethylphosphonium chloride,

bromide and iodide,

tributylbenzylphosphonium chloride, bromide and iodide,

tributylvinylphosphonium chloride, bromide and iodide,

bis Z-hydroxypropyl) diphenylphosphonium chloride,

bromide and iodide,

2-hydroxypropylmethyldiphenylphosphonium chloride,

bromide and iodide,

tributyl-2,4-dichlorobenzylphosphonium chloride,

bromide and iodide,

2,5-dichlorobenzylphosphonium chloride, bromide and iodide,

3,4-dichlorobenzylphosphonium chloride, bromide and iodide,

tris(2-cyanoethyl)-o-viny1benzylphosphonium chloride,

bromide and iodide,

tris 2-cyanoethyl -p -vinylb enzylpho s phonium chloride,

bromide and iodide,

tris 2-cyanoethyl) -m-vinylb enzylpho sphonium chloride,

bromide and iodide,

triphenyl-o, m and p-vinylbenzylphosphonium chloride,

bromide and iodide,

tris(Z-carboxyethyl)phenylphosphonium chloride,

bromide and iodide,

bis Z-carboxyethyl bis Z-cyanoethyl) phosphonium chloride, bromide and iodide,

tributyl-(o, m or p-vinylbenzyl)phosphonium chloride,

bromide and iodide,

ethyltriphenylphosphonium chloride, bromide and iodide,

2-hydroxyethyltriphenylphosphonium chloride, bromide and iodide,

tributyl 2- (Z-methyl- 1 -imidazolyl) ethyl] phosphonium chloride, bromide and iodide,

tricyclohexyl [2-( Z-methyll-imidazolyl) ethyl] phosphonium chloride, bromide and iodide,

tributyl(diethylaminoethyl)phosphonium chloride,

bromide and iodide,

2-b utenylbis(2-cyanoethyl) phenylphosphonium chloride,

bromide and iodide,

4-octenyl 2-hydroxyethyl methylphenylpho sphonium chloride, bromide and iodide,

2-cyanoethyl (4-cyanobutyl) diphenylphosphonium chloride, bromide and iodide,

diethylphenyl(4-hydroxybutyl)phosphonium chloride,

bromide and iodide,

allylbenzyl(8-hydroxyoctyl)methylphosphonium chloride,

bromide and iodide,

carboethoxyethyl( 8-cyanooctyl diphenylphosphonium chloride, bromide and iodide,

bis 8-carboxyoctyl) dimethylphosphonium chloride,

bromide and iodide,

bis (Z-cyanoethyl) (p-bromobenzyl) phenylphosphonium chloride, bromide and iodide,

bis(2-cyanoethyl) (4-carboxybutyl)phenylphosphonium chloride, bromide and iodide,

bis(Z-cyanoethyl)naphthylphenylphosphonium chloride,

bromide and iodide,

diphenylmethyl [4- (Z-methyll-imidazolyl butyl] phos phonium chloride, bromide and iodide,

tris Z-cyanoethyl) (Z-methylnaphthyl phosphonium chloride, bromide and iodide,

tris 2-cyanoethyl) 2,4- (dibromobenzyl) phosphonium chloride, bromide and iodide,

methyldiphenyl 8-( Z-methyl-l-imidazolyl) octyl] phosphonium chloride, bromide and iodide,

diphenylmethyl(p-iodobenzyl)phosphonium chloride,

bromide and iodide,

tris Z-cyanoethyl) 3-chloro-2-methyl-naphthyl) phosphonium chloride, bromide and iodide,

tributyldimethylaminoethylphosphonium chloride,

bromide and iodide,

2-carboethoxypropyltriphenylphosphonium chloride,

bromide and iodide,

carbooctoxymethyltriphenylphosphonium chloride,

bromide and iodide,

dibutylaminoethyltrimethylphosphonium chloride,

bromide and iodide,

dibenzyl(p-chlorobenzyl) propylphosphonium chloride,

bromide and iodide,

cyanomethyltrimethylphosphonium chloride, bromide and iodide,

butyltris(p-nitrobenzyl)phosphonium chloride, bromide and iodide,

tetra-3-carboxypropenyl-l-phosphonium chloride,

bromide and iodide,

tetra-Z-carboxyvinyl propenyl-l-phosphonium chloride,

bromide and iodide,

trimethyl-3-carboxypropeny1-l-phosphonium chloride,

bromide and iodide,

9 triphenyl-Z-carboxyvinyl-l-phosphonium chloride,

bromide and iodide, tris (Z-cyanoethyl -2-car-bomethoxyvinylphosphonium chloride and bromide, tris (Z-cyanoethyl) -2-carbomethoxypropenyl-3- tions on the present invention except as set forth in the appended claims. All parts and percentages are by weight unless otherwise specified.

Any appropriate fiame-retardance test may be used to determine the flame retardance properties of any specific phosphonium chloride and bromide, 5 compound. One test which is reasonably eflicient is that triphenyl-4-carbomethoxybutenyl-4-phosphonium designated as a modified version of ASTM test D-635- chloride and bromide, 56T. The specifications for this test are: a specimen, triphenyl-2-carbomethoxypropenyl-3-phosphonium 5" in length, 0.5" in width and 0.045" in thickness, is chloride and bromide, 10 marked at the 1" and 4" lengths and is then supported tributy-2-carbomethoxypropenyl-3-phosphonium with its longitudinal axis horizontal and its transverse chloride and bromide, axis inclined at 45 to the horizontal. A Bunsen burner tributyl-S-carbomethoxypentenyl-Z-phosphonium with a 1" blue flame is placed under the free end of the chloride and bromide, strip and is adjusted so that the flame tip is just in con tributyl-Z-carbomethoxyhexenyl-l-phosphonium l5 tact with the strip. At the end of 30 seconds, the flame is chloride and bromide, removed and the specimen is allowed to burn. If the specitris(2-cyanoethyl)-2-carboethoxyvinyl phosphonium men does not continue to burn after the first ignition it chloride and bromide, is immediately recontacted wvith the burner for another tris(Z-cyanoethyl)-3-carbobutoxypropenyl-3- 30 second period. If, after the two burnings, the strip phosphonium chloride and bromide, 20 is not burned to the 4" mark, the specimen is designated dioctylvinyl-Z-carbomethoxypropenyl-3-phosphonium as self-extinguishing or flame-retardant.

chloride and bromide, tris 2-hydroxyethyl) -2-carbomethoxypropenyl-3- EXAMPLE 1 Phosphomum chloride and bromide 85 parts of polyethylene and 15 parts of triphenylmethb1s(l'carbmfypmpyl){nethyl'z'carvomethoxypropenY]'3' 25 ylphosphonium bromide are milled together on a two Phosphomum chlonde and bromlde roll mill at about 170 C. The resulting milled composimethymaPhEhYlPhenflQ'carbmefl}XyPmPenY1'3' tion is molded into strips 5" in length, 0.5" wide and ,Phosphomum Chlonde and bromlde 0.45" in thickness and said strips are then subjected to the dlbenzylethyl'z'caTbQmethOXYPmPeDYI'3Phosphomum 30 above specified flame-retardance test. The strips pass the lde andbmmlde, test and are therefore designated as flame-retardant. p-nitrobenzyltris(2-carbomethoxy propenyl-3) Following the procedure of Example 1, the following ,phosphomum f and bromide examples were carried out utilizing different flame-retris (dimethylarninoethyl)-2-carbornethoxypropeny tardant agents and various thermoplastic resin polymers. Phosphomum chlol'lde and bl'omlde, The results of these examples are set forth in Table I ms(2'carb{nethXyehY1)'zcarbQmethoxypropenyl'3 below. In each instance, the resultant plastic-monophochlonde and bromlde, sphonium halide mixture passed the fiame-retardance test y YP P Y and was designated as flame and fire-retardant. In the Phlonde and f table PE.=polyethylene; PP=polypropylene; PMMA: tr1butyl- 2-carboxyv1nyl phosphonium chloride and 40 polflmethylmethacrylate); p 1 1 acid); PS: bromlde poly(styrene); PF=polyformaldehyde; CA=cellulose mixtures thereof, other compounds having mixed subacetate; (BisPhen1A'PhSgen Stituems andthe1ike action product); AN=acrylonitrile; ST=styrene and The following examples are set forth for purposes of BD=b11tadieI1e- The term y refers to the reaction illustration only and are not to be construed as limitaproduct of adipic acid and hexamethylene diamine.

TABLE I Flame Retardant Ex Polymer R R1 R2 R3 X Percent 2 PP Q Q Q CH8 Br 15 3 PP Same as above Same as above Same as above CH3 I 10 (1 do d0 CHBCH2 Br d0 CH3(CH2)2 Br -do do --d0 CH2=CHCH2 B1 30 Same as above 15 (10... CHQCHZOCCHZ 20 NCGHQOHZ CH3 1O NCCHZCHZ CH3 10 CH2CH2 CHsCHg 2O NCCHzCHg NCCH CH NCCHiCHg CH;(CH2)1 Br 19. PE NCCHQCHZ NCCH CH NOOHzCH CHQ=CHCH2 Br 20 PMMA NCCHgOHg NCCHzOH NOOH CHg CH2=CHCH2 Br 20 21.-. PE NOCH2CH; NCCHgCIIg NCCHQCH; GI-I OHCH, c1 30 1 7 EXAMPLE 99 To a suitable reaction vessel equipped with gas inlet and outlet, thermometer and stirrer are added 19.4 parts of methyl-Z-(chloromethyl) acrylate in 40 parts of aceto- 18 Analysis.Calcd. for C H 'ClN O P (percent): P, 9.45; Cl, 10.82. Found (percent): P, 9.54; CI, 10.74.

Infrared analysis shows (mull in mineral oil) a carbonyl band at 1707 cmf a H C==CH band at 1630 1 -1 nltrlle and 27 parts of tr1s(2-cyanoethy1) phosphme with 5 C bands at 1225 and 1132 stirring. A vigorous exotherm occurs and a solid precipi- Follqwlng the procedure Example 99, Vanous other tates. The reaction mixture is kept in a nitrogen atmos- Phosphmes were reacted Wlth other unsaturated halo phere for two hour At th d of thi ti th lid i genated compounds. The results are set forth in Table 'II, removed by filtration, washed with acetonitrile and anbelow.

TABLE II Temp, Time, Yield, Ex. Tertiary phosphine Unsaturated halide 0. hours Solvent percent Product 100 26 parts of triphenyl phosphine. 13 parts of methyl-2- 81 2. Acetonitrile, 97 Triphenyl-2-carbornethoxy- (chloromethyl) acrylate. propenyl-3-phosphonium chloride.

101 27 parts of tributyl ph0sphine 19 parts of methyl-2- 75 2 do. 74 Trihutyl-2-carbomethoxy- (ehloromethyl) acrylate. propenyl-3-phosphonium chloride.

10.. 30 parts of dimethyloctyl 17 parts of 3-ehloroacrylic 65 4 do 8O (Z-carboxyvinyl) dimethyloctyl phosphine. acid. phosphonium chloride.

103 26 parts of divinylmethyl 16 parts of butyl 2- 50 4 .d0 76 2-0arbobutoxy-propenyl-B- phosphine. (chloromethyl) methyl-divinylphosaerylate. phonium chloride.

104 28 parts 01 triscyanomethyl 15 parts of 4-chl01'0-3- 75 2 ..do 82 3-carl'uoxypropenyl-l-triscyanophosphine. butenoic acid. methylphosphoniumchloride.

105 17 parts of 3-hydroxy-0ctylidi Sparts of methyl-3-chlo- 80 2 5 d0 79 2-carbomethoxyviny1-3-hypropenyl-3-phosphine. rocrylate. droxy oetyl-dipropenyl- 3-ph0sphonium chloride.

106 parts 01 trinaphthyl phosphine 6 parts of methyl 5-ehloro- 73 3 5 do 83 4-carbornethoxy-I-bnten-l-yl- 4-pentenoate. trinaphthyl phosphonium chloride.

107 21 parts 01 benzyldiphenyl 11 parts of 3-brorn0acrylic 68 4 do 71 Benzyl-2-carboxyvinyl-diphenyl phospine. acid. phosphonium bromide.

108 36 parts of tris(2,4-diehlorobenzyl) 20 parts of ethyl 3-bromo- 77 2 do 73 2-carbocthoxy-viny1-tris(2,4-

phosphine. acrylate. chlorobenzyl) phosphonium bromide.

109 parts of bis(pnitropl1enethyl) 9 parts of ethyl 2-(bromo- 80 1 5 d0 87 2-carboethoxy-propenyl-B- mcthylphosphine. ethyl) acrylate. methyl bis(p-nitr0phenethyl) phosphom'um bromide.

110 26 parts of tris (dimethyl- 15 parts of ethyl 2 75 3 d0 75 2 carboethoxy 3-tris(dimethylaminoethyl) phosphine. (bromoethyl) acrylate. aminoethyl) phosphoninm bromide.

111 9 parts of tris(carbometh- 6 parts of methyl 4-bromo- 73 3 Butanol 82 4carbomethoxy-l-buten-l-yloxyrnethyl) phosphine. 4-pentenoate. tris(carbomethoxymethyl) phosphonium bromide.

112 5 parts of trivinyl phosphine 3 parts of 2-chloroacrylic 78 2. 5 Acetonitrile 91 l-carboxyvinyl-trivinyl phosaeid. phonium chloride.

113 42 parts of bis(2-carboxycthyl) parts of 4-chlor0-3- 65 4 d0 88 Bis(flcarboxyethyl)-3-carboxyphenylphosphine. butenoie acid. propenyl-l-phenyl-phosphom'um chloride.

114 17 parts of dimethyl 8 parts of propyl-3- 4 d0 93 2carbopropoxy-vinyl-dimethyl- (p-vinylbenzyl) phosphine. bromoacrylate. pvinylbenzyl phosphonium bromide.

115 19 parts of tris(p-bromobenzyl) 10 parts of ethyl-2-(2- 4 d0 71 Z-earlboeth0xy-1buten4yltris phosphine. chloroethyl) acrylate. (p-bromobcnzyl)phosphonium chloride.

116 10 parts of tris (Z-dimethyl- 10 parts of ethyl 5-br0n1o- 60 4 do 52 4-carb0ethoxy-l-buten-l-yl-tris aminobutyl) phosphine. 4pcnten0ate. (Z-dimethylaminobutyl) phosphonium bromide.

117.... 14 parts of tris (l-carhoethoxy- 8 parts of 3-chl0r0acrylic 75 3 do 80 Tris( l-carboethoxypropyl)-2- propyl) phosphine. acid. carboxyvinyl phosphonium chloride.

1 0.1 parts liydroquinone added to retard polymerization.

hydrous ether and dried in vacuum. 34 parts of tris(2-cy- What is claimed is: anoethyl)-2-carbomethoxypropenyl-3-phosphonium chlo- 1. A flame-retardant composition consisting essentially ride are recovered (73% yield). The chloride is a white of a thermoplastic polymer selected from the group consolid having a melting point of 151154 C. dec. he sisting of styrene polymers containing a majority of a solid is water-soluble and insoluble in hot methyl methastyrene monomer, polymer of an a-olefin, polyamides havcrylate. ing recurring amide groups as integral parts of the main 19 polymer chain, polymers of methyl methacrylate containing a majority of methyl methacrylate, acrylonitrilebutadiene-styrene polymers containing a minority of styrene and styrene polymer-butadiene polymer blends and a flame-retarding amount of a monophosphonium halide having the formula wherein R, R R and R are individually selected from the group consisting of alkyl (C -C alkenyl (C -C cyano, hydroxy, imidazolyl, and carboxy substituted alkyl, 1- 8), y v m) aralkyl r- 11), y halo, polyhalo, and nitro ar-substituted aralkyl (C C dialkylaminoalkyl (C -C carboalkoxyalkyl (C -C carboxyalkenyl (C C and carboalkoxyalkenyl (C -C radicals, and X is selected from the group consisting of a bromine, chlorine, and iodine radical.

2. A flame-retardant composition according to claim 1 wherein the thermoplastic polymer is a polymer of an a-olefin.

3. A flame-retardant composition comprising polyethylene and a flame-retarding amount of methyltriphenylphosphonium iodide.

4. A flame-retardant composition comprising polyethylene and a flame-retarding amount of tris(2-cyanoethyl)- methylphosphonium iodide.

5. A flame-retardant composition comprising polyethylene and a flame-retarding amount of dichlorobenzyl-tris(2 cyanoethyl)phosphonium chloride.

6. A flame-retardant composition comprising polystyrene and a flame-retarding amount of tris(2-cyanoethyl)- methylphosphonium iodide.

7. A flame-retardant composition according to claim 1 wherein the thermoplastic polymer is poly(methy1 methacrylate).

-8. A flame-retardant composition comprising poly- (methyl rnethacrylate) and a flame-retarding amount of methyltriphenylphosphonium iodide.

9. A flame-retardant composition comprising poly- (methyl methacrylate) and a flame-retarding amount of tris(2.-cyanoethyl)methylphosphonium iodide.

10. A flame-retardant composition comprising poly- (methyl methacrylate) and a flame-retarding amount of dichlorobenzyl-tris(Z-cyanoethyl)phosphonium chloride.

11. A flame-retardant composition comprising polystyrene and a flame-retarding amount of dichlorobenzyltris (.Z-cyanoethyl) phosphonium chloride.

12. A composition comprising a p0ly(hexamethylcnc adipamide) polymer and a phosphonium halide selected from the group consisting of methyl triphenyl phosphonium chloride, methyl triphenyl phosphonium bromide, methyl triphenyl phosphonium iodide, benzyl triphenyl phosphonium chloride, benzyl triphenyl phosphonium bromide and benzyl triphenyl phosphonium iodide, said phosphonium halide being present in an amount of up to five percent by weight based upon the weight of said polymer.

References Cited UNITED STATES PATENTS 2,837,446 6/1958 Cohen et al 117139.5 X 3,05 4,698 9/ 1962. Wagner.

FOREIGN PATENTS 885,200 4/ 195 8 Great Britain. 1,101,351 3/1961 Germany.

OTHER REFERENCES Rokey, K. W., Plastics (London), 26, No. 283, 103-10 6 (1961).

HOSEA E. TAYLOR, Primary Examiner R. A. WHITE, Assistant Examiner US. Cl. X.R.

UNI'IED STA'IES lPA'illN'l OFFICE CER'ITIF'I'CA'IE 0F CORRECTION Patent No. v gzm m nntedjieptember dd, 1920 lnventofls) Helga Currier Gillhgm; Allan Ellis Sher-r; Harvey Gerald Klein It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column a, line :1, insert, as a new paragraph, The thermoplastic polymers into which the flame-retardant agents may be incorporated to produce the novel compositions of the present invention, are generally the vinyl type polymers wherein the monomeric material is polymerized, by any known method, via the vinyl unsaturation therein. Column 5, line 56. insert, as a new paragraph, As mentioned above, we have discovered the addition of monophosphonium halides to a thermoplastic resin results in the production of resinous compositions having excellent flame-retardant properties. According; to the present invention, any monophosphonium halide, stable to processing conditions may be used for this purpose. Column 3. line 6?, insert as the first sentence of the last paragraph, These monophosphonium halides can be incorporated into the resin by any know method. Column 5, line 7, "ocetnylphosphonium" should read octenylphosphonium Column 5, line 35, "tetrahydroxymethyphosphonium" should read tetrahydroxymethylphosphonium --;'Column 5, line 51, "tetracarboxylmethylphosphonium" should read tetrecarboxymethylphoephonium Column 6, line 19, "tetrabenylphosphonium" should read tetrabenzylphosphonium Column 6, line n5, "diode" should read iodide Column 9, line 11,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PAGE 2 Patent No. 5,550,164 Dated September dd, 1970 Inventor(s) Helen Currier Gillham; Allan Ellis Sherr;

Harvey Gerald Klein It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

"tributy should read tributyl Column 9, line +5, insert as a new paragraph, It is also within the scope of the present invention to incorporate such ingredients as plasticizers, dyes, pigments, stabilizers, antioxidants, antistatic agents and the like to out novel compositions. Column 10, line 56, "fi'ame should read flame Columns 9 and 10, Example 18, Table I, under the heading R "NCCH CH should read NCCH. CH Columns ll and 14, Example 24' Table I, under the heading R "NCCH; CH should read NCCH CH Columns ll and ld, Example 55, Table I, under the heading R, "CH CHCH should read CH CHCH Columns 11 and 1d, Example OH OH 54, Table I, under the heading R, "CH CHCH" should read OH CH CHCH Column 17, line '75, "he should read The Columns 1'? and 18, Example 107, Table II, "phospine" should read phosphine Signed and sealed this 28th day of December 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents 

